package netutil

import (
	"net"
	"strings"
)

func IsLocalOrPrivateHost(host string) bool {
	host = strings.ToLower(strings.TrimSpace(host))
	if host == "" {
		return false
	}
	if host == "localhost" || strings.HasSuffix(host, ".localhost") || host == "host.docker.internal" {
		return true
	}
	ip := net.ParseIP(host)
	return ip != nil && IsLocalOrPrivateIP(ip)
}

func IsLocalOrPrivateIP(ip net.IP) bool {
	if ip == nil {
		return false
	}
	if ip.IsLoopback() || ip.IsPrivate() || ip.IsUnspecified() || ip.IsLinkLocalUnicast() || ip.IsLinkLocalMulticast() {
		return true
	}
	ip4 := ip.To4()
	if ip4 == nil {
		return false
	}
	return ip4[0] == 100 && ip4[1] >= 64 && ip4[1] <= 127
}